1. Field of the Invention
The present invention relates to a sample testing system, and particularly to a sample testing system that includes a transporting part for transporting a rack that accommodates sample containers. Also, the present invention relates to a transporting apparatus.
2. Description of the Related Art
Conventionally, there are known sample testing apparatuses that include a transporting apparatus for transporting sample containers each containing a sample. As for such a sample testing apparatus, there is a case where after a sample is loaded into, and tested by, the sample testing apparatus, retesting of the sample becomes necessary. Whether or not retesting of the sample is necessary is determined after the sample is loaded into the sample testing apparatus and a result of testing the sample by the sample testing apparatus is obtained. Accordingly, the sample that has been loaded stands by on a transporting path until it is determined whether or not retesting of the sample is necessary. This hinders the following samples from moving toward a collecting unit, resulting in stagnant sample transportation. Therefore, sample processing cannot be performed efficiently.
U.S. Pat. No. 6,117,392 discloses, as a sample testing apparatus that enables efficient sample processing, an automatic analyzing apparatus that includes: an analyzing unit for analyzing samples; and a transporting apparatus for transporting, to the analyzing unit, racks each holding multiple sample containers containing samples. The transporting apparatus of the automatic analyzing apparatus includes: a transporting line for transporting each rack that holds multiple sample containers; a standby unit for taking in, from the transporting line in a direction perpendicular to the transporting line, a rack that holds samples having been measured by the analyzing unit, and for allowing the rack to stand by therein until it is determined whether or not retesting of the samples in the rack is necessary; and a returning line, provided separately from the transporting line, for sending a rack that holds samples to be retested, to the upstream side of the transporting line. Racks transported on the transporting line are each, after the analyzing unit has performed sample loading from each sample container thereof, taken in and held by the standby unit until it is determined whether or not retesting of the samples therein is necessary. Then, a rack that holds samples for which retesting has been determined to be necessary, is returned from the standby unit through the returning line to the upstream side of the transporting line (i.e., to a position at which the transporting starts). By having the above configuration, a rack that holds samples that are waiting for necessity/unnecessity determination for retesting can be kept standing by at the standby unit, during which the following rack that holds samples for which retesting has been determined to be unnecessary can be collected into a collecting unit. Thus, the transporting of the racks is not stagnated, and the processing can be performed efficiently.
However, in the automatic analyzing apparatus described in U.S. Pat. No. 6,117,392, the transporting line is capable of transporting racks only in a single direction. Therefore, although the transporting line can transport racks from the analyzing unit to the standby unit or to the collecting unit, the transporting line cannot transport a rack that holds samples that require retesting, from the standby unit to the analyzing unit. For this reason, it is necessary to provide, separately from the transporting line, the returning line for transporting the rack from the standby unit to the upstream side of the transporting line. This results in a problem that the analyzing apparatus becomes large sized.